Increasing　Investigations　show　that　photosensitizers　(PSs)　which　target　mitochondria　are　useful　for　enhancing　photodynamic　therapy　(PDT)　efficacy.　Herein,　we　carefully　designed　and　synthesized　four　triphenylphosphonium　(TPP)-modified　boron　dipyrromethene　(BDP)-based　PSs　through　Cu(I)-assisted　＂3+2＂　cycloaddition　reaction.　All　of　them　exhibit　intense　red　light　absorption　with　maxima　between　659　and　663　nm,　considerable　fluorescence　emission　with　quantum　yields　of　0.16-0.23,　high　singlet　oxygen　generation　efficiency　ranging　from　0.22　to　0.34,　excellent　mitochondria-targeting　ability,　and　good　biocompatibility.　Upon　illumination,　they　induce　significant　cancer　cell　death　through　a　mitochondria-related　apoptosis　pathway.　The　IC50　values　of　these　BDP　dyes　against　MCF-7　cells　were　determined　to　be　as　low　as　0.046-0.113　mu　M　under　rather　low　dosage　of　light　irradiation　(1.5　J.cm(-2)).